In 3GPP, standardization of LTE (Long Term Evolution)-A (Advanced) as a method to expand LTE has been in progress.
CA (Carrier Aggregation) has been introduced to LTE-A to further increase the communication rate.
Here, CA is a technique to improve the peak rate and throughput of a mobile station UE and is implemented by performing communication with two or more CCs (Component Carriers).
Meanwhile, MLB (Mobility Load Balancing) is a technique specified in LTE Release-9 in 3GPP.
MLB specified in LTE Release-9 is a technique which involves, in an environment where only macrocells are present, adjusting mobility-related parameters by taking into consideration the loads on neighboring cells (macrocells). For example, by using MLB, a radio base station eNB#1 that manages a cell #1 and a radio base station eNB#2 that manages a cell #2 exchange load information therebetween while a mobile station UE is in a connected state in the cell #1, and adjust handover-related parameters (e.g. CIO, Hysteresis, etc.) to promote handover of the mobile station UE from the cell #1 to the cell #2, if the load on the cell #2 is found to be less than the load on the cell #1.